A central control device required by some networks (e.g., LANs or MANs) to provide such centralized functions as remodulation, retiming, message accountability, contention control, diagnostic control, and access to a gateway. 2. A control center of a CATV system, where incoming signals are amplified, converted, processed, and combined into a common cable for transmission to customers. The headend usually includes antennas, preamplifiers, frequency converters, demodulators, modulators, processors, and other related equipment. Synonym cable headend.